Currently, the United States pharmaceutical market only has three major weight loss drugs available: Xenical (orlistat), Meridia (sibutramine), and Phentermine. Many doctors and obese patients alike are hoping for new and more effective weight loss pills to emerge. Two new weight loss pills currently being produced and studied in Europe are rimonabant (Acomplia) and taranabant.

Rimonabant seemed like a promising new weight loss pill, but the FDA became concerned about some serious psychiatric side effects such as depression and suicidal tendencies. Taranabant, so far, is showing fewer and milder side effects even though both drugs work similarly and produce comparable weight loss.

Both new weight loss pills affect the receptors in the body's system that regulates things such as energy level, food intake, metabolism and also fear and anxiety. So far, the reason for the differences in side effects is unknown.

Dosage could be a factor. Less taranabant is needed to produce similar weight loss. Rimonabant and taranabant also have slight differences in how they interact with the receptors. It is unclear for now why there are fewer side effects in one new weight loss pill and not the other.

Rimonabant, or Acomplia, is already being sold in Europe, but it doesn't seem as though this new weight loss pill will make its debut in the United States for awhile. Merck, the pharmaceutical company developing taranabant, seems hopeful that they will be able to file for FDA approval in the summer of 2008. Still, the trials are not over and it may be awhile before this new weight loss pill is available stateside.

For many obese patients, hope in the form of a new, effective weight loss pill can't come soon enough. It's amazing that with all the pharmaceuticals out on the market that there are only three approved weight loss pills available.

The problem is that the part of obesity that can be controlled by the individual is directly related to human behavior. The part of obesity that cannot be controlled is not completely understood.

We are left in a conundrum of sorts. If a person is obese due to lack of proper nutrition and exercise, he or she can be helped, but only if that person is willing to help him or herself. If the person has in earnest tried to lose weight and cannot, than medical intervention may be necessary. Unfortunately, every new weight loss pill that comes about seems to have potentially detrimental side effects. The FDA cannot be blamed for not allowing the sale of drugs such as Rimonabant. The duty of the FDA is to protect the public from potentially harmful substances. In light of the deaths that occurred through the use of Fen-phen, the FDA has reason to be gun shy.

Ultimately, science needs to keep striving to develop a new weight loss pill to help otherwise helpless obese patients; more importantly, however, they need to strive to understand obesity on all levels.